<template>
  <div class="app-container">

    <!-- 添加章节按钮 -->
    <div>
      <el-button type="primary" @click="addChapter()">添加章节</el-button>
    </div>

    <!-- 章节列表 -->
    <ul class="chapterList">
      <li v-for="chapter in chapterList" :key="chapter.id">
        <p>
          {{ chapter.title }}
          <span class="acts">
            <el-button type="text" @click="addVideo(chapter.id)">添加课时</el-button>
            <el-button type="text" @click="editChapter(chapter.id)">编辑</el-button>
            <el-button type="text" @click="removeChapterById(chapter.id)">删除</el-button>
          </span>
        </p>
        <!-- 视频 -->
        <ul class="chapterList videoList">
          <li v-for="video in chapter.children" :key="video.id">
            <p>
              {{ video.title }}
              <el-tag v-if="!video.videoSourceId" size="mini" type="danger">
                {{ '尚未上传视频' }}
              </el-tag>
              <span class="acts">
                <el-tag v-if="video.free" size="mini" type="success">{{ '免费观看' }}</el-tag>
                <el-button type="text" @click="editVideo(chapter.id, video.id)">编辑</el-button>
                <el-button type="text" @click="removeVideo(video.id)">删除</el-button>
              </span>
            </p>
          </li>
        </ul>
      </li>
    </ul>

    <!-- 章节表单对话框 -->
    <chapter-form ref="chapterForm" />

    <!-- 课时表单对话框 -->
    <video-form ref="videoForm" />

    <div style="text-align:center">
      <el-button type="primary" @click="prev()">上一步</el-button>
      <el-button type="primary" @click="next()">下一步</el-button>
    </div>
  </div>
</template>

<script>
  import {
    getNestedTreeList,
    removeById,
    save,
    getById,
    updateById
  } from '@/api/chapter'
  import {
    removeVideoById
  } from '@/api/video'
  // 引入组件
  import ChapterForm from '@/views/course/components/Chapter/Form'
  // 引入组件
  import VideoForm from '@/views/course/components/Video/Form'

  export default {
    // 注册组件
    components: {
      ChapterForm,
      VideoForm
    },
    data() {
      return {
        chapterList: [] // 章节嵌套列表
      }
    },

    created() {
      this.fetchNodeList()
    },

    methods: {
      editVideo(chapterId, videoId) {
          this.$refs.videoForm.open(chapterId, videoId)
      },
      removeVideo(videoId) {
        this.$confirm('此操作将永久删除该课时, 是否继续?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }).then(() => {
          return removeVideoById(videoId)
        }).then(response => {
          this.fetchNodeList()
          this.$message.success(response.message)
        }).catch((response) => {
          if (response === 'cancel') {
            this.$message.info('取消删除')
          }
        })
      },
      // 添加课时
      addVideo(chapterId) {
        this.$refs.videoForm.open(chapterId)
      },
      // 编辑章节
      editChapter(chapterId) {
        this.$refs.chapterForm.open(chapterId)
      },
      // 添加章节
      addChapter() {
        this.$refs.chapterForm.open()
      },
      // 删除章节
      removeChapterById(chapterId) {
        this.$confirm('此操作将永久删除该章节，是否继续?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }).then(() => {
          return removeById(chapterId)
        }).then(response => {
          this.fetchNodeList()
          this.$message.success(response.message)
        }).catch((response) => {
          if (response === 'cancel') {
            this.$message.info('取消删除')
          }
        })
      },

      // 获取远程数据
      fetchNodeList() {
        getNestedTreeList(this.$parent.courseId).then(response => {
          this.chapterList = response.data
        })
      },

      // 上一步
      prev() {
        this.$parent.active = 0
      },

      // 下一步
      next() {
        this.$parent.active = 2
      }
    }
  }
</script>

<style>
  .chapterList {
    position: relative;
    list-style: none;
    margin: 0;
    padding: 0;
  }

  .chapterList li {
    position: relative;
  }

  .chapterList p {
    float: left;
    font-size: 20px;
    margin: 10px 0;
    padding: 10px;
    height: 70px;
    line-height: 50px;
    width: 100%;
    border: 1px solid #DDD;
  }

  .chapterList .acts {
    float: right;
    font-size: 14px;
  }

  .videoList {
    padding-left: 50px;
  }

  .videoList p {
    float: left;
    font-size: 14px;
    margin: 10px 0;
    padding: 10px;
    height: 50px;
    line-height: 30px;
    width: 100%;
    border: 1px dashed #DDD;
  }
</style>
